Liquid crystal contact thermography was used to assess both normal control patients and patients with temporomandibular joint and myofascial pain. The technique appears capable of detecting temperature changes around the TMJ and muscles of mastication. Patients with painful internal derangements of the TMJ have warm areas over the joint, and those with myogenic facial pain symptoms have areas of variable temperature over the masseter muscle. After successful nonsurgical treatment of these conditions, the thermograms return to normal.